2003 LEXUS LS430 Diagram AC

Fig. 43: Identifying Seat Climate Control Blower Connector Terminals And Seat Heater Connector
Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: REPLACE SEAT CLIMATE CONTROL BLOWER (CLIMATE CONTROL ECU)
CIRCUIT DESCRIPTION
The thermistor circuit inside the seat climate controller or the thermistor circuit of the rear seat heater may
become open or short circuit, or the thermistor's output values may not change because it is damaged. If these
situations occur, output from the Peltier element, fan motor, rear seat heater, idle-up signal (not including the
front passenger side) will be stopped and the indicator illuminates according to blinking pattern 4.
WIRING DIAGRAM

Fig. 44: Climate Control Does Not Operate (Blinking Pattern 4) Wiring Diagram (1 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 45: Climate Control Does Not Operate (Blinking Pattern 4) Wiring Diagram (2 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.CHECK SEAT HEATER (INDICATOR)
a. Check that the climate control indicator is blinking.
Result:

NG: REPAIR OR REPLACE AIR DUCT
OK: REPLACE SEAT CLIMATE CONTROL CONTROLLER (SEATBACK OR SEAT
CUSHION)
CIRCUIT DESCRIPTION
If the climate control seat does not operate, the seat climate control blower (climate control ECU) or the wire
harness may be malfunctioning.
WIRE DIAGRAM
Fig. 51: Climate Control System Does Not Operate On Driver Side
- Wire Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT FUSE (D S/HTR)
a. Remove the D S/HTR fuse from the driver side J/B.
b. Measure the resistance of the fuse.
Standard: Below 1 ohms
NG: REPLACE FUSE
OK: Go to next step
2.CHECK WIRE HARNESS (SEAT CLIMATE CONTROL BLOWER (CLIMATE CONTROL
ECU) - BATTERY)
a. Disconnect the C20 blower connector.

CIRCUIT DESCRIPTION
If the climate control seat does not operate, the seat climate control blower (climate control ECU) or the wire
harness may be malfunctioning.
WIRE DIAGRAM
Fig. 58: Climate Control System Does Not Operate On Passenger Side
- Wire Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT FUSE (P S/HTR)
a. Remove the P S/HTR fuse from the driver side J/B.
b. Measure the resistance of the relay.
Standard: Below 1 ohms
NG: REPLACE FUSE
OK: Go to next step
2.CHECK WIRE HARNESS (SEAT CLIMATE CONTROL BLOWER (CLIMATE CONTROL
ECU) - BATTERY)
a. Disconnect the C21 blower connector.
b. Measure the voltage of the wire harness side connector.
Standard:
TESTER CONNECTION AND SPECIFIED CONDITION
Tester ConnectionConditionSpecified Condition

CIRCUIT DESCRIPTION
If the climate control seat does not operate, the seat climate control blower (climate control ECU), the climate
control switch or the wire harness may have a malfunction.
WIRE DIAGRAM
Fig. 65: Climate Control System Does Not Operate On Rear Side
- Wire Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE

Fig. 5: Combination Meter System Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
GATEWAY:

Fig. 29: Combination Meter Inner Circuit Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.